The invention relates to sliding vane rotary power devices, and more particularly to internal combustion engines, pumps, compressors, fluid-driven motors, expander devices, fluid-driven pumps and compressors or throttling devices, where various ones of those devices differ from others by a simple modification of a central stator member.
Rotary power device of the radial vane type are characterized in having a rotor assembly comprising a number of vanes spaced about the rotor and dividing the rotor chamber into discrete cavities. As the rotor turns, the vanes follow the wall contour of the rotor chamber and thereby provide cavities that rotate with the rotor.
Sliding vane rotary devices generally comprise straight vanes slidably received within respective slots radially formed in a rotor. As the rotor spins, vanes are driven outward by centrifugal forces to an extent constrained by the wall contour, so as to execute radially reciprocating motion as the rotor spins. In an effort to increase the outward centrifugal force, a variety of sliding rotary devices have been developed. One class of devices uses a biasing spring disposed at the base of each vane. Another class uses a pair of controlling sidewall cam grooves engaged by sub-shafts fixed to lower side portions of a vane. Still another class uses a transfer passage connecting a pressurized fluid to the base of the vanes. Problems generally encountered by such devices include fluid slip, leakage, complexity associated of the disposition of intake and discharge, and lack of an ability to functionally modify the device to operate as either a pump or an IC engine. Examples of rotary devices of the above type can be found in United States patent such as U.S. Pat. No. 6,030,195 to Pingston, U.S. Pat. No. 4,355,965 to Lowther, U.S. Pat. No. 5,415,141 to McCann, U.S. Pat. No. 4,353,337 to Rosaen, and U.S. Pat. No. 4,018,191 to Lloyd.
This invention relates to a rotary power device of the radial vane type characterized in having a rotor assembly comprising a number of vanes equally spaced about the rotor and dividing the rotor chamber into discrete cavities. As the rotor turns, these vanes follow the wall contour of the rotor chamber and thereby provide cavities that rotate with the rotor and that expand and contract as the rotor turns. Various combinations of smooth wall contours and rotational arrangements are provided in different embodiments of the invention in order to cause an appropriate number of expansions and contractions of a cavity during the course of a rotation. In embodiments calling for a single expansion and a single contraction, a substantially circular rotor chamber may be used in combination with an eccentric shaft. In embodiments calling for two or more cycles of expansion and contraction, a rotor chamber having the appropriate number of lobes may be used in combination with a rotor turning about an axis through a center of the rotor chamber.
There are several preferred inventive combinations of rotor chamber shape and rotational arrangements for the rotor. Some of these are:
A preferred two-cycle engine having a rotor chamber in which the wall contour forms a substantially circular wall eccentrically enclosing the rotor and forming two symmetrical halves of expanding and contracting cavities. In operation as a two-cycle engine, each cavity executes compression, power, and intake and exhaust scavenging processes during the course of each rotation of the rotor.
A preferred rotary single-action pump having a rotor eccentrically disposed in a substantially circular rotor chamber so that the cavities expand and contract once during each rotation of the rotor assembly.
A preferred four-cycle engine having a rotor chamber comprising an oval-shaped wall. The rotor chamber has a center coinciding with a shaft axis and forming four quadrants. Two diametrically opposed quadrants provide expanding cavities that are alternated by another two quadrants of contracting cavities. As a cavity moves through the four quadrant ranges it executes intake, compression, power and exhaust processes.
A preferred double-action pump having a rotor concentrically disposed with respect to an elliptical chamber. In a double-action pump the cavities expand and contract twice during each rotation of the rotor assembly.
The present invention comprises a rotary power device that can be configured, among other things, to serve as either a two-cycle or a four-cycle internal combustion engine, or as a single-action or double-action pump by replacement of a stationary central member. Preferred embodiments of the invention comprise a generally toroidal rotor assembly fixedly secured to an end shaft and rotatably carried at one end of an external stator housing. The preferred rotor comprises a central bore communicating with a plurality of radial compartments that are open to a peripheral surface of the rotor and that will be hereinafter referred to as open-ended compartments.
The preferred rotor block also comprises a plurality of radial slots disposed in alternating relation with the radial compartments. Each radial slot is connected to an adjacent radial compartment by a transfer passage connecting the base of the slot with the compartment. An external stator portion of the device defines an internal volume that, when combined with the stationary central stator portion, defines a chamber for receiving the rotor. The preferred rotor chamber, when viewed in a medial section perpendicular to a rotational axis of the device, may appear as an ellipse or as a circle. Moreover, the rotor chamber may be concentric or eccentric with respect to the rotational axis of the device. Furthermore, preferred devices comprise an internal stator fixedly secured to the external stator and rotatably enclosed, with clearance, within the central bore of the rotor. The internal stator comprises channels connected to ports communicating with inner openings of the rotor compartments. As the rotor spins, a cavity formed between two adjacent vanes enclosing a radial compartment intermittently communicates with the ports in the internal stator so as to perform intake, compression, and power and exhaust functions. In addition to embodiments serving as internal combustion engines, the rotary device of the invention can function as pump or compressor by replacing the internal stator with one having the appropriate port and channel configuration.
One object of some embodiments of the invention is to provide an improved radial vane rotary power device that is light in weight, small in size and that has the minimum number of parts.
Another object of some embodiments of the invention is to provide a rotary power device that can be easily converted to other type of rotary power device such as, a pump, a compressor, or a work exchanger device by a simple modification or replacement of a central stationary member.
Another object of some embodiments of the invention is to provide a rotary power device that closely approximates continuous intake, compression, combustion and discharge processes.
Another object of some embodiments of the invention is to provide a rotary power device characterized by reduced noise and vibration.
Another object of some embodiments of the invention is to provide a rotary power device with minimum fluid slip and leakage.
These and other objects and advantages of the present invention will be apparent from the following detailed description and the appended claims. Although it is believed that the foregoing recital of features and advantages may be of use to one who is skilled in the art and who wishes to learn how to practice the invention, it will be recognized that the foregoing recital is not intended to list all of the features and advantages. Moreover, it may be noted that various embodiments of the invention may provide various combinations of the hereinbefore recited features and advantages of the invention, and that less than all of the recited features and advantages may be provided by some embodiments.